Trailer slider locking system

ABSTRACT

A trailer slider locking system includes body rails longitudinally slidable relative to a suspension frame side rail. The body rails have holes providing multiple suspension positions. A pin locking system includes a pin moveable between retracted and locked positions. An end of the pin is received in one of the holes in the locked position. The pins have tapered ends so that the pin will extend through the body rail hole prior to advancing to the fully locked position.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/141,628, which was filed May 31, 2005, now U.S. Pat. No. 8,025,302issued Sep. 27, 2011.

BACKGROUND OF THE INVENTION

The present invention relates to a trailer slider locking system, andmore particularly, the invention relates to a pin configuration thatbetter ensures pin engagement with the body rails.

Trailer slider locking systems are utilized on tractor trailers toadjust the longitudinal position of a slider carrying the trailersuspension beneath the trailer body. Trailer body rails are supported ontop of and slide relative to suspension frame side rails. The trailerbody rails include a series of holes providing multiple body positionsrelative to the trailer suspension. A mechanical linkage supported on aslider, or trailer suspension frame is used to bias spring-loaded pinsto a locked position in which the pins are received in holes in thetrailer body rails. The pins lock the side and body rails together. Thepins are moved to a retracted position using the mechanical linkage tolongitudinally adjust the position of the trailer body rail relative tothe trailer suspension frame.

Trailer locking systems often have a problem in which the pins do notengage the body rails or fully extend through the holes in the bodyrails. If the pins are not fully locked, the trailer body may sometimesslide relative to the trailer suspension frame during vehicle operation,possibly resulting in a damaging collision between the trailer body andsuspension frame. For example, if hard braking occurs when the pins arenot fully locked, prior art pins will jump past body rail holes as thetrailer body rails move forward relative to the trailer suspensionframe, which is being slowed or stopped due to braking. Therefore, whatis needed is a trailer sliding locking system that enables better pinengagement in the locked position.

SUMMARY OF THE INVENTION AND ADVANTAGES

The inventive trailer slider locking system includes a pair of bodyrails longitudinally slidable relative to suspension frame side rails.The body rails have holes providing multiple suspension positions. A pinlocking system includes a pin moveable between retracted and lockedpositions. An end of the pin extends through one of the holes in thelocked position. The system typically includes at least one pin on eachside. In one example, the pin has a first centerline and the holes havea second centerline. The end of the pin extends through the hole withthe centerlines offset from one another in the locked position.

In one example of the invention, first and second holes along the bodyrail provide a distance that is greater than a distance provided byfirst and second locking pin centerlines. In another example, thedistance between the first and second holes is less than the distancebetween the first and second locking pin centerlines. For example, thepins are smaller than the holes so that there is a greater longitudinallength along which the pins can be received in the body rail holes.

In another example, the pins have tapered ends so that the pin willextend through the body rail hole prior to advancing to the fullyextended and locked position. This ensures that the pin preventsrelative movement between the trailer body and suspension frame even ifthe pin is not fully extended due to debris or misalignment.

Another example includes an aperture in the pin on the opposite side ofthe pin end received in the body rail hole. The aperture permits an endof the linkage to be received within the aperture in the event that thepin cannot be advanced from the retracted position to the lockedposition. In this manner, if one of the pins cannot move to the fullylocked position for some reason it will not prevent the other pins frommoving to the locked position by inhibiting the movement of themechanical linkage that actuates the pins.

Accordingly, the present invention provides a trailer sliding lockingsystem that enables better pin engagement in the locked position.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention can be understood by referenceto the following detailed description when considered in connection withthe accompanying drawings wherein:

FIG. 1 is a perspective view of the inventive trailer slider lockingsystem.

FIG. 2A is a cross-sectional view in a locked position.

FIG. 2B is a cross-sectional view in a retracted position.

FIG. 2C is a cross-sectional view in a bound position.

FIG. 3A is a schematic view of the prior art in a transient trailer bodyposition.

FIG. 3B is a schematic view of the inventive pin in a transient trailerbody position.

FIG. 4A is a schematic view of the prior in the transient embodimentposition with the pin partially aligned with the body rail holes.

FIG. 4B is a schematic view of the inventive pin in the transientembodiment position with the pin partially aligned with the body railholes.

FIG. 5A is a schematic view of the prior art with the trailer body in analigned pin position with the centerline of the pin partially offsetfrom the centerline of the trailer body hole.

FIG. 5B is a schematic view of the inventive pin with the trailer bodyin an aligned pin position with the centerline of the pin partiallyoffset from the centerline of the trailer body hole.

FIG. 6A is a schematic view of one inventive pin configuration.

FIG. 6B is a schematic view of another inventive pin configuration.

FIG. 6C is a schematic view of another inventive pin configuration.

FIG. 6D is a schematic view of another inventive pin configuration.

FIG. 7A is a schematic view of an inventive pin arrangement in oneposition relative to the trailer body holes.

FIG. 7B is a schematic view of an inventive pin arrangement in anotherposition relative to the trailer body holes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 depicts a trailer slider system 10 including a suspension frame12 supporting an axle 14. The axle 14 is supported for articulation onthe suspension frame 12 by upper 16 and lower 18 arms. An air bag 20 isarranged between the axle 14 and suspension frame 12. The suspensionconfiguration shown in

FIG. 1 is only exemplary, and one of ordinary skill in the art willunderstand that the inventive trailer slider system can be used with anysuspension configuration.

A pin locking system 22 is supported on the suspension frame 12. The pinlocking system 22 includes a handle 24 that is moved laterally by avehicle operator to actuate the system between retracted and lockedpositions. While a manual system is shown, it should be understood thatan automated or semi-automated system may also be used. The handle 24 isconnected to a crank 26 secured to shaft 28 that is rotationallysupported by the suspension frame 12. The shaft 28 includes a pair ofcam mechanisms 30 each of which pivotally support ends of linkages 32.Cages 34 are secured to the suspension frame 12 and house pins 36 thatare actuated by the linkages 32 between retracted and locked positionsin response to manipulation of the handle 24. While the arrangement offour pins 36 as shown is typical, fewer or greater pins may also beused.

Referring to FIG. 2A, an inventive pin 36′ is shown supported by a siderail 38 of the suspension frame 12. The cage 34 is supported on the siderail 38. An end 42 of the linkage 32 extends into the cage 34 formanipulating the inventive pin 36′ between locked (FIG. 2A) andretracted (FIG. 2B) positions. An end cap 40 is secured to the end 42and engages a flange 46 of the pin 36′. A first spring 44 biases the pin36′ to the locked position. The spring 44 is arranged between a rearwardportion of the cage and the end cap 40. A second spring 48, whichgenerates a biasing force less than the first spring 44, is arrangedbetween the flange 46 and a forward portion of the cage 34 for biasingthe pin 36′ to the retracted position. The handle 24 is pulled outwardto move the pins 36′ from the locked position to the retracted position.The linkages 32 compress the first spring 44 by pulling it towards therearward portion of the cage 34 with the end cap 40. Removing thebiasing force of the first spring 44 from the flange 46 enables thesecond spring 48 to urge the pin 36′ from the locked position (FIG. 2A)to the retracted position (FIG. 2B).

Occasionally the pin 36′ will bind in holes 54 in the side rails 38 orholes 56 in the body rails 52 when the handle 24 is pushed to return thepins 36′ from the retracted position (FIG. 2B) to the locked position(FIG. 2A). In prior art arrangements, a binding pin or the pin beingblocked by the body rails could prevent the other pins from being biasedto the locked position by the first springs 44 because the end 42 of thelinkage 32 associated with the bound pin 36′ would collide with the rearof the pin 36′. This might prevent the other linkages 32 from movingtoward the forward portions of the cages 34, which enables the firstsprings 44 to advance. To address this problem, one aspect of thepresent invention incorporates apertures 50 in the rear of the pins 36′to accommodate the end 42 of the linkage 32 if the pin 36′ should bind,as shown in FIG. 2C. The end 42 extends into the aperture 50 permittingthe other linkages to move toward the forward portion of the cage 34permitting the first springs 44 to expand and bias the pins 36′ to thelocked positions.

In another feature of this invention, the inventive pins 36′ includetapered ends 58 having tapered surfaces 60 that enable the pin end toextend through the body holes 56 even if the pins 36′ do not fully alignwith the body holes 56. That is, the centerline of the pins 36′ and bodyholes 56 can be offset by a substantial amount and yet the pins 36′ willextend through the body holes 56 thereby preventing the body rails 52from moving relative to the side rails 38 even if the pins 36′ and bodyrail holes 56 are misaligned. Prior art systems have required relativelyprecise alignment between the centerlines of the pins and body railholes, which has resulted in the pins not always fully engaging the bodyrails. This result may permit the body rails to move relative to theslider under braking conditions.

Referring to FIGS. 3B, 4B and 5B, the tapered end 58 includes an apex 62at a terminal end of the pin 36′. In the example shown in the Figures,the pin 36′ includes a periphery, which in one example is a cylindricalsurface, having opposing sides 64, 66. The periphery is spaced axiallyfrom the apex 62 in the example shown; a tapered surface 60 extends fromthe apex 62, which lies along long side 64, to a short side 66 oppositethe long side 64. In the example shown, the tapered surface 60 is agenerally planar surface and the apex 62 is offset from the centerline.The tapered surface 60 enables the pin 36′ to extend through the hole 56in the body rail 52 prior to a centerline of the pin 36′ and acenterline of the body hole 56 being substantially aligned. Thus, thebody rail 52 is prevented from moving relative to the side rails 38 whenthe pins 36′ are misaligned with the body holes 56. The flat provided bythe tapered surface 60 prevents the pin 36′ from rotating.

FIG. 3A depicts a prior art pin in a transient position, and FIG. 3Bdepicts the inventive pin 36′ in the same transient position. As theposition of the body rail 52 is adjusted by the vehicle operator, thepin 36′ has not extended through the body rail hole 56, as shown in FIG.4A with the prior art system. As shown with the inventive pin in FIG.4B, the long side 64 of the pin 36′ extends into the body hole 56. Thelong side 64 provides a surface that is normal to the body rail 52 sothat forward movement of the body rail 52 will be prevented.

FIG. 5A depicts the prior art pin 36 in a position in which the pin issubstantially aligned with the body hole 56. However, contact between anedge of the moving body rail hole 56 and chamfer 68 on the end of thepin 36 may create a force F that prevents the pin 36 from extendingthrough the hole 56. The tapered surface 60 of the inventive pin 36′better ensures that the pin 36′ continues to extend to the fully lockedposition as the tapered surface 60 slides along the edge of the bodyhole 56.

FIGS. 6A-6D generally depict several example pin locking systems 22having different pin combinations and orientations. For example, FIG. 6Aillustrates the inventive pins 36′ arranged at the forward side of thetrailer slider system with the tapered surfaces 60 facing forward.Conventional pins 36 are arranged at the rear side of the trailer slidersystem. Arranging the tapered surfaces 60 so they face forward betterensures that pins 36′ will extend through the body holes 56 if thetrailer body shifts forward during a braking operation, as illustratedin FIGS. 4B and 5B. FIG. 6B is similar to FIG. 6A except the inventivepins 36′ are used at each of the four corners of the trailer slidersystem with tapered surfaces 60 facing forward. FIG. 6D is similar toFIG. 6A except the forward and rearward pins are swapped.

FIG. 6C illustrates a pin locking system 22 having the inventive pin 36′on each of the four corners with the tapered surfaces of the forward andrearward pin sets arranged in opposite directions. The forward pin setensures that the trailer body is locked to the suspension frame if thebody moves forward relative to the frame, and the rear pin set ensuresthat the trailer body locks to the suspension frame in the less likelyevent of the trailer body moving rearward relative to the suspensionframe during vehicle operation with the pins misaligned with the bodyrail holes 56.

FIGS. 7A and 7B depict one side of a pin locking system 22 that betterensures pin engagement with the body holes 56 when there is amisalignment between the pins 36 and holes 56. Either conventional pins36 or the inventive pins 36′ may be used in this configuration. It isdesirable that the body holes 56 be larger than the pin diameter 36, forexample, by as much as 25 percent or more. However, it is to beunderstood that the relative size between the diameter of the pins 36and holes 56 may vary based upon the particular trailer slider system.The body holes 56 have centerlines that define a first distance C1between the centerlines. The pins 36 have centerlines that define asecond distance C2 between the centerlines. The distance C2 is greaterthan the distance C1 (see FIG. 7A). Having the centerline distancesunequal from one another and the pins 36 smaller than the holes 56enables the pins 36 to extend through the holes 56 even when the pins 36are not aligned with the holes 56. In another embodiment (see FIG. 7B),the distance C2 is less than C1.

For the configuration shown in FIG. 7B, as the body rail 52 slidesrelative to the frame rail in the forward direction, the forward pinwill be received in the forward body hole 56. As the body rail 52continues to move forward, the rearward pin will extend through therearward body hole 56 so that opposing sides of the pins 36 are in closeproximity to opposing sides of the holes 56 on that rail. In thismanner, at least one pin on each side will be engaged in a hole toprevent relative movement between the body rail and side rail. Asillustrated in FIG. 5A, prior art systems require more precise alignmentbetween the centerline of the pin 36 and body hole 56. The configurationshown in FIG. 7A operates similarly to the embodiment shown in FIG. 7B,except the rear pin engages the hole first.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology that has been used is intended to bein the nature of words of description rather than of limitation.Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:
 1. A pin locking system comprising: a pin movablebetween a retracted position and a locked position, said pin having afirst end configured to extend through a hole in a side rail in saidlocked position and a second end configured to receive input to movesaid pin to said retracted position, and wherein said first end of saidpin includes a tapered surface; a resilient member biasing said pintoward said locked position; a link member coupled to said second end ofsaid pin, said link member configured to be coupled to an input member;and wherein said pin includes a first body portion having a firstdiameter and a second body portion having a second diameter greater thansaid first diameter, and wherein said resilient member reacts againstsaid second body portion to move said pin to said locked position;wherein the pin comprises a first pin and the side rail comprises afirst side rail, and including a second pin having a first endconfigured to extend through a hole in a second side rail laterallyopposite of the first side rail when in a locked position, said firstand second pins comprising a forward pin set, and including a third pinhaving a first end configured to extend through a hole in the first siderail when in a locked position and a fourth pin having a first endconfigured to extend through a hole in the second side rail when in alocked position, and wherein said third and fourth pins comprise arearward pin set that is longitudinally spaced from said forward pinset, and wherein said first ends of said second, third, and fourth pinshave a tapered surface; wherein said tapered surfaces of said forwardand said rearward pin sets face in opposite directions.
 2. The pinlocking system according to claim 1, wherein said tapered surfaceextends across an entire cross-section of said first end.
 3. The pinlocking system according to claim 1, wherein said tapered surfaces ofsaid forward pin set face a forward direction and said tapered surfacesof said rearward pin set face a rearward direction.
 4. The pin lockingsystem according to claim 1, wherein said tapered surface extends froman apex at one pin edge to an opposite pin edge.
 5. The pin lockingsystem according to claim 1, wherein said tapered surface comprises agenerally flat surface that tapers from one edge of a distal end face ofsaid first end toward an opposite edge of said distal end face.
 6. Thepin locking system according to claim 1, wherein said link memberscomprises a rigid link having a first end coupled to an input member anda second end that is coupled to said second end of said pin.
 7. The pinlocking system according to claim 6, wherein said input member comprisesa shaft that is configured to rotate at least one cam mechanism, andwherein said first end of said rigid link is coupled to said cammechanism.
 8. The pin locking system according to claim 1, wherein saidtapered surfaces of said forward and said rearward pin sets extendsacross a substantial portion of an end surface of said first end of eachof said first, second, third, and fourth pins.
 9. A trailer sliderincluding a body rail longitudinally slideable relative to a suspensionframe side rail, one of the body and suspension frame side rails havingholes providing multiple suspension positions, the trailer slidercomprising: a pin locking system having first and second pins movablebetween retracted and locked positions, said first and second pins beinglaterally spaced apart from each other, and wherein each of said firstand second pins includes a first end configured to extend through one ofthe holes in said locked position and a second end configured to receiveinput to move said first and said second pins to said retractedposition; first and second resilient members that bias said first andsaid second pins to said locked position; a linkage coupled to saidsecond ends of said first and said second pins, said linkage configuredto be coupled to an input member; and wherein each of said first ends ofsaid first and second pins comprise an end face having a taperedsurface; wherein said first and said second pins comprise a forward pinset, and including a third pin configured to extend through one of theholes in the body and suspension frame side rails in the locked positionand a fourth pin configured to extend through one of the holes in thebody and suspension frame side rails in the locked position, and whereinsaid third and fourth pins comprise a rearward pin set that islongitudinally spaced from said forward pin set, and wherein said thirdand fourth pins each have an end face with a tapered surface; whereinsaid tapered surfaces of said forward and said rearward pin sets face inopposite directions.
 10. The trailer slider according to claim 9,wherein said first and said second pins are defined by a diameterextending from one pin edge to an opposite pin edge, and wherein saidtapered surface extends entirely across the diameter of said first andsaid second pins.
 11. The trailer slider according to claim 10, whereineach of said tapered surfaces comprises a constant taper.
 12. Thetrailer slider according to claim 9, wherein said tapered surfaces ofsaid forward pin set face a forward direction and said tapered surfacesof said rearward pin set face a rearward direction.
 13. The trailerslider according to claim 9, wherein each of said first and said secondpins includes a first body portion having a first diameter and a secondbody portion having a second diameter greater than said first diameter,and wherein a respective one of said first and said second resilientmembers react against said second body portion to move an associated oneof said first and second pins to said locked position.
 14. The trailerslider according to claim 9, wherein said tapered surface comprises agenerally flat surface that tapers from one edge of said end face ofeach of said first and second pins toward a respective opposite edge ofsaid end face of each of said first and second pins.
 15. The trailerslider according to claim 9, wherein said input member comprises a shaftthat is configured to rotate at least one cam mechanism, and whereinsaid linkage comprises a first rigid link having one end coupled to saidcam mechanism and an opposite end coupled to said second end of saidfirst pin and a second rigid link having one end coupled to said cammechanism and an opposite end coupled to said second end of said secondpin.
 16. The trailer slider according to claim 9, wherein said taperedsurfaces extend across a substantial portion of an end surface of saidfirst end of each of said first, second, third, and fourth pins.
 17. Atrailer slider locking mechanism comprising: a suspension frame siderail having at least one side rail hole; a trailer body rail slidablerelative to said suspension frame side rail, said trailer body railhaving at least one body rail hole to be aligned with said at least oneside rail hole to achieve a lock position; first and second pins movablebetween retracted and locked positions, said first and second pins beinglaterally spaced apart from each other, and wherein each of said firstand second pins includes a first end configured to extend throughaligned side rail and body rail holes in said locked position and asecond end configured to receive input to move said first and saidsecond pins to said refracted position; first and second resilientmembers that bias said first and said second pins to said lockedposition; a linkage coupled to said second ends of said first and saidsecond pins, said linkage configured to be coupled to an input member;and wherein each of said first ends of said first and second pinscomprise an end face having a tapered surface; wherein said first andsaid second pins comprise a forward pin set, and including a third pinconfigured to extend through aligned side rail and body rail holes insaid locked position and a fourth pin configured to extend throughaligned side rail and body rail holes in said locked position, andwherein said third and fourth pins comprise a rearward pin set that islongitudinally spaced from said forward pin set, and wherein said thirdand fourth pins each have an end face with a tapered surface; whereinsaid tapered surfaces of said forward and said rearward pin sets face inopposite directions.
 18. The trailer slider locking mechanism accordingto claim 17, wherein said first and said second pins are defined by adiameter extending from one pin edge to an opposite pin edge, andwherein said tapered surface extends entirely across the diameter ofsaid first and said second pins.
 19. The trailer slider lockingmechanism according to claim 18, wherein each of said tapered surfacescomprises a constant taper.
 20. The trailer slider locking mechanismaccording to claim 17, wherein said tapered surfaces of said forward pinset face a forward direction and said tapered surfaces of said rearwardpin set face a rearward direction.
 21. The trailer slider lockingmechanism according to claim 17, wherein each of said first and saidsecond pins include a first body portion having a first diameter and asecond body portion having a second diameter greater than said firstdiameter, and wherein a respective one of said first and said secondresilient members reacts against said second body portion to move anassociated one of said first and second pins to said locked position.22. The trailer slider locking mechanism according to claim 17, whereinsaid tapered surface comprises a generally flat surface that tapers fromone edge of said end face of each of said first and second pins toward arespective opposite edge of said end face of each of said first andsecond pins.
 23. The trailer slider locking mechanism according to claim17, wherein said input member comprises a shaft that is configured torotate at least one cam mechanism, and wherein said linkage comprises afirst rigid link having one end coupled to said cam mechanism and anopposite end coupled to said second end of said first pin and a secondrigid link having one end coupled to said cam mechanism and an oppositeend coupled to said second end of said second pin.
 24. The trailerslider according to claim 17, wherein said tapered surfaces extendacross a substantial portion of an end surface of said first end of eachof said first, second, third, and fourth pins.